During industrial production processes solids or liquids are converted in order to produce a new end product from an input product. In the chemical industry, for example, the production process may require that the input product for the production of the end product occurs in different states of aggregation.
For example, containers are alternately filled with fillings or materials are heated and reprocessed at a particular temperature. In order to be able to monitor the production process, an information about the actually prevailing state of the respective product should be available which information is as accurate as possible.
For the accurate registering of the states, in particular of fill levels or pressures in containers, measuring devices are thus employed at many positions in the production process, which can determine physical characteristics of the material.
The results of the measurements are converted for the presentation in a form that can be interpreted by a user. For the presentation of measured values, displays are used, from which a user can read off a measured result.
The reading off of the displays can depend on the external environment, and due to environmental influences the reading can be impaired such that the reading off is no longer possible.